The terror attacks of 2001 ushered in a decade of wars that shattered Iraq and Afghanistan, leaving the world's only superpower robbed of its confidence and stripped of its illusions

In the United States they speak of the "lost decade". The moment it began is obvious: the morning of 11 September 2001, when the world's lone superpower fell victim to the most devastating terrorist attack of modern times. Its end, however, is harder to date.

In the United States they speak of the "lost decade". The moment it began is obvious: the morning of 11 September 2001, when the world's lone superpower fell victim to the most devastating terrorist attack of modern times. Its end, however, is harder to date.

One answer is 1 May this year, when a team of Navy Seals tracked down and killed Osama bin Laden at his hideaway in Pakistan. A circle was complete; after almost 10 years of frustration, false leads and continuous war, the master planner of 9/11 had finally paid for his crime. But look at it another way and the answer is not so obvious.

In these 10 years America has lost much, in terms of lives, treasure and reputation. Most of all, perhaps, it has lost its illusions. One, that its home territory was invulnerable, beyond the reach of hostile foreigners, vanished on that terrible Tuesday morning. But a decade on, another no less cherished illusion has disappeared as well: the certainty that whatever happened in the world beyond, America was a place of infinite opportunity and ever-growing prosperity.

Formally, of course, the anniversary of 9/11 is today. But when one era closes, another begins. In a sense, this lost decade ended 72 hours earlier, on Thursday evening, when President Obama presented Congress with his plan to prevent the US economy from slipping back into the worst economic recession since the 1930s. It was a call to arms that mirrored George W Bush's in the same place when he declared his "war on terror". But this time, Mr Obama did not even mention 9/11. Instead, as rarely before, an American president acknowledged bitter economic reality. It has taken a decade.

The attacks of 11 September 2001 changed everything. If the 20th century in reality ended on Christmas Day 1991, at the moment the Soviet Union passed into history, the 21st century began only on that perfect autumn morning along the US mid-Atlantic seaboard, when apocalypse arrived. Things happened in between: the Balkan wars, a genocide in Rwanda, the painful birth of a new Russia, as well as the death of an English princess and the adventures of a White House intern. History, however, seemed on holiday until 9/11.

At each of the three sites – Ground Zero in New York, the Pentagon in Washington and the wooded meadow near Shanksville, Pennsylvania, where United's Flight 93 crashed – elaborate memorials have been erected and solemn ceremonies will today take place. But, however moving, these cannot convey the enormity of the event.

Even now, our minds do not have space to accommodate simultaneously the tragedies of that day: the destruction, the 3,000 lost lives, the shattered families, the heroism of New York's firefighters and the bravery of the passengers on UA93, who sacrificed themselves to prevent a direct hit on the US capital (with Congress in full session), just 20 minutes' flying time away. Even now, those images of planes ripping like darts into gleaming skyscrapers amid a giant burst of yellow, orange and black seem surreal, something from the realm of comic strip fantasy, not the recent history of lower Manhattan.

And then there's everything that flowed from 9/11: the wars, the changes in a wounded America's attitude to the world, either "with us or against us", as well as in foreign attitudes towards America, and the later terrorist attacks in Bali, London, Madrid and elsewhere. The sole comfort, such as it is, is that 11 September 2001 could have been even more dreadful; the initial plan was an operation involving not four but 10 hijacked aircraft, striking targets on the West Coast as well.

Could it have been prevented? Perhaps, but not without a huge slice of luck. The report on the attacks, published here in 2004 by the non-partisan 9/11 Commission and still a terrific read, identifies "four kinds of failure: in imagination, policy, capabilities and management". They are best dealt with in reverse order.

The management shortcomings consisted mainly in the shameful lack of co-operation between the FBI and the CIA, the two main counter-terrorism agencies, and the slow response of FBI headquarters to warnings from its agents in the field. Had the CIA told the bureau in 2000 and 2001 that two al-Qa'ida suspects who were among the future hijackers were in the US, the two might have been placed under surveillance; conceivably, the hijacking might have been disrupted.

In terms of capability, ie the military resources and strategies devoted to the terrorist threat, the Pentagon was still relying on Cold War thinking and Cold War weapons. Moreover, the country's defences faced outward, to counter any threat from abroad, not ones originating at domestic civil airports. On the policy front it was a similar story: before 9/11, the biggest foreign preoccupations were the Balkans, Saudi Arabia and the Middle East conflict. The US was well aware of al-Qa'ida – Bill Clinton had sent cruise missiles against its bases in 1998. Beyond that though, what was to be done: invade Afghanistan?

Today, much has changed. The FBI and the CIA seem to be working more smoothly together, though some tensions remain. Of less certain value, the federal government now boasts a revamped intelligence structure that places the 15 separate existing agencies under a single director of national intelligence, as well as a new bureaucratic behemoth, the Department of Homeland Security. The efforts of the latter may be seen in the numbing security procedures at airports, a domestic counterpart to the precautions that have turned US embassies abroad (not to mention the State Department in Washington) into concrete fortresses that are the very antithesis of diplomatic outreach.

And no one can complain about a lack of focus on terrorism by the Pentagon or White House. Counter-insurgency and asymmetric warfare are now core military missions. Unmanned drones are more widely used than ever; elite special forces have been greatly enlarged. On 1 May, they proved their worth with the spectacular Seals raid that killed Bin Laden and captured a trove of vital al-Qa'ida documents.

That was an obvious and long-overdue success. A less trumpeted success is that, despite every prediction to the contrary in the aftermath of 9/11, there have been no more attacks on mainland America. It has taken 10 years, but the US may be close to a knockout blow against al-Qa'ida, at least the original al-Qa'ida that Bin Laden ran.

However, of the failures identified by the commission, the biggest was that of imagination. Even with the full advantage of hindsight, it is still hard to grasp how a group of fanatics and social misfits, numbering half the size of an army platoon, in an operation costing just $500,000 and run from one of the poorest, most backward corners of the earth, could have wreaked such mayhem on the most powerful country in history – mayhem that resulted in direct insurance losses of $40bn, about the same as for Hurricane Katrina.

Yes, counter-terrorism specialists knew that, in theory, something like that could happen; much has been made of the daily intelligence report sent to President George Bush on 6 August 2001, a month before the attacks, with the heading "Bin Laden Determined to Strike in US", and warning of "suspicious activity in this country consistent with preparations for hijackings or other types of attacks". But the when, where and how were unspecified. What, in practice, was the much-maligned Bush supposed to do?

However, after 9/11, he made up for previous inactivity with a vengeance. In response to the attacks, directly or indirectly, the US embarked on three wars: first an entirely reasonable one against the Taliban government in Afghanistan that sheltered Bin Laden and his organisation and refused to turn them over; then the disastrous war of choice against Iraq; and third, the all-encompassing global "war on terror", aka GWOT.

In 2009, that moniker was amended to the more soothing Overseas Contingency Operations. But GWOT continues, more quietly but no less relentlessly than before. Those insurance losses pale into insignificance as well. According to one academic study, the final bill for this age of wars, the longest in US history, could run to $4trn.

The unquantifiable costs were no less great. The "war on terror" and all that flowed from it – the torture of suspects, the endless imprisonment of "enemy combatants" denied the most basic right of habeas corpus, CIA "ghost camps", extraordinary renditions, Guantanamo Bay, Abu Ghraib – did shocking damage to America's reputation. Even the election of the first black president who, having spent part of his childhood in the Muslim world, was peculiarly well-equipped to see the US as others see it, has failed to expunge the image of arrogance, unilateralism and sheer ignorance created by his predecessor. Indeed, Obama has continued many Bush-era policies, albeit with the roughest edges removed. Contrary to his initial promises, Guantanamo Bay remains open for business, and terrorist suspects will continue to be tried (if they are tried at all) in military courts. Drone attacks are more frequent than ever, despite the resentment they cause in populations the US is trying to win over.

At home, the panic of a decade ago has subsided. With a fatalism not usually associated with the most can-do country on God's earth, Americans increasingly accept that terrorism is a part of the world we live in. But the trauma of that terrible day lingers, and America's centres of power remain very jumpy places. Experts have long warned that a new attack might involve WMD, even some form of nuclear device. When Washington was struck by an earthquake last month, a single thought flashed through every mind: was this al-Qa'ida's 10th anniversary present? And not unreasonably so. Statistically, if the ground beneath the White House starts to shudder, the cause is rather more likely to be the work of terrorists than a quake in seismically tranquil Virginia.

Could there be another 9/11? A repeat of what happened then is highly unlikely, not least because people are alert. Witness the action of the passengers who overpowered the shoe-bomber Richard Reid in December 2001, and the would-be "underwear-bomber" who tried to blow up a Northwest Airlines plane as it prepared to land in Detroit on 25 December 2009. As usual, though, we are fighting the last war. Do the authorities have the imagination to foresee what shape the next attack might take?

Now to a hypothetical, but very relevant question: what if 11 September had never happened? Would America be very different? In some respects, the answer, of course, is yes. Airports would be more welcoming places. Deadly bombings and the mass murder of civilians would still be regarded as a blight on less fortunate lands, not for the US, blessed as it is by friendly neighbours and vast oceans that separate it from the world's turmoil.

It is even possible that George Bush, whose presidency seemed destined for mediocrity even before 9/11, might have been defeated after a single term. That he squeaked through in November 2004 was largely due to the country's unwillingness to change commander-in-chief in the midst of three wars. But whoever followed him in the Oval Office would surely not have been spared the worst economic and financial collapse since the Great Depression. And the consequences of this crisis – not terrorism – are the overwhelming concern and challenge for Americans today.

In fact, 9/11 does bear some blame for the severity of the crisis and lack of options open to Obama. Bush chose to pay for his wars with borrowed money, adding to the debt that ties his successor's hands. But you can't blame Osama bin Laden for the government's mania to deregulate.

Nor was Bin Laden responsible for the years of excessively low interest rates set by the Federal Reserve that fed the reckless mortgage lending that led to the sub-prime crisis, or for the equally reckless behaviour of the banks. Nor has he anything to do with America's chronic inability to live within its means. Consider the price of gold, safe haven par excellence in times of uncertainty. After 11 September, it shot up from $215 to $287 an ounce, but soon levelled out. A decade later it stands close to $1,900, six times higher.

And in politics too, the story is the same. Partisanship and endless squabbling have reduced the system to near-terminal dysfunction. Today's rancour and gridlock in Washington can be traced to several causes. They include the Republicans' belief that they were played for suckers by a cynical Bill Clinton, the left's belief in a "vast right-wing conspiracy" that led to Clinton's impeachment, and its enduring conviction that the 2000 election was stolen by a combination of Bush, a rigged voting system in Florida and the US Supreme Court.

Among those causes, however, 9/11 does not figure. In fact, the attacks generated a short-lived but extraordinary political unity. Today, the Patriot Act of October 2001 that gave sweeping extra powers to the police and other government agencies to combat terrorists is widely criticised, and not only from the left, as an encroachment on basic civil liberties. Few now remember that the bill passed the Senate by a majority of 98 votes to one – or that in a supremely moving moment on the evening of the terrible day itself, Senators and Congressmen, Democrats and Republicans alike, stood together on the steps of the Capitol and broke into an unscripted rendering of "God Bless America".

At that moment, Bush, his popularity at a stratospheric 90 per cent, could have used the moment to do bold things, unimaginable in normal times, and which might have mitigated the economic crisis that lay ahead. He could have reversed some of his tax cuts to pay for his wars; he could have imposed a petrol tax to raise revenue and reduce America's crippling dependency on oil from the very region where the terrorists originated. But for lack of will, or lack of imagination, he blew his chance. Then, just as now, compromise had to be on Republican terms: in other words, my way or the highway.

If Bin Laden can be blamed for anything, it is for causing the US to take its eye off the ball. The "war on terror" eclipsed all else. In its name the US would spend its blood and treasure to secure a safer world, in the mistaken belief that nothing could not be achieved by the might of American arms and the imposition of Western-style democracy. All the while, China and other rising industrial powers moved quietly but steadily forward. They captured American markets and American jobs, and bought vast quantities of US debt to enable the country to continue to consume more than it produced. The world's mightiest military power was now the world's biggest debtor.

And all the while, the truth was concealed. From Washington, presidents have continued to peddle the doctrine of "American exceptionalism". Their country was different from other countries, Bush told them, it had a special place in the world. It could make its own rules, and everything would come right in the end. In the immediate aftermath of 9/11, such language was a necessary morale-booster for a traumatised nation. These days it is wilful evasion of reality. To Obama's credit, his speech on Thursday evening, acknowledging that the US faced a protracted "national crisis", contained remarkably little that sugared the pill of truth.

Whether his plan will make it across the great political divide is quite another matter. Nothing suggests Republicans have changed their calculation that by thwarting Obama at every turn, they increase their chances of recapturing the White House next year. But they should be careful. Political and economic cycles do not always coincide.

Intrinsic to America's can-do mentality is the expectation of a quick solution to every problem. Their failure to deliver instant results is a prime reason why Obama and, even more so, Congress are held in such low esteem. Bush was re-elected in 2004, but in the 2006 mid-terms the country returned control of Capitol Hill to the Democrats. In 2008, Obama and his party swept the board, only to lose the House of Representatives a bare two years later, on the wrong end of the biggest landslide in seven decades. The end product of this cycle of frustration is the anti-government Tea Party, which sends its breed of conservative Republicans to Washington with the express aim of dismantling Washington. And in 2012, who knows? Perhaps voters will send Obama packing. Perhaps they will say to obstructionist Republicans, enough is enough. But Bin Laden has little to do with these convulsions. They are caused by a far more insidious foe – the destruction not of buildings and lives, but of once-bedrock certainties, undermined not by al-Qa'ida but by global economic trends that, if anything, are likely to intensify in the decades ahead.

Ever since the Depression, a prime tenet of "the American Dream" has been that each generation will be better off than the one before it. Until the turn of the century, that was true. But since 2001 the poverty rate has risen; the median income has declined; the number of people without health insurance has grown; and the gap between rich and poor is wider than at any time since the 1929 Wall Street Crash.

Most dispiriting of all is unemployment. The headline figure is 9 per cent; throw in those who are not counted, or who have given up looking for work, and the true rate may be close to 17 per cent. No wonder two-thirds of the population believe the country is in decline, both at home and in terms of its influence abroad.

A decade after the horrors of 9/11, the world's lone superpower is learning anew one of history's constants, that economic crises can be even more intractable than wars. Wars unite, and what would the country not give to rediscover the sense of unity spawned in September 2001. But the idea of Democrats and Republicans holding hands and singing "God Bless America" to celebrate the passage of an economic grand bargain to put the country to rights? That wouldn't be an illusion, but a delusion.

Ten years of fear, conflict and the erosion of civil liberties

Ten years ago yesterday, the US was continuing to revel in the fall of communism, the dotcom revolution and minor sex scandals involving the ever-frisky members of Congress. If this wasn't, in the still-fashionable thesis, the end of history, it seemed as if it were taking an extended vacation. Since then, there has been rather too much history. And the cost in lost lives has been appalling – at least 236,500 people killed in Afghanistan, Iraq and Pakistan, according to the "Costs of War" study by the Watson Institute for International Studies at Brown University in Rhode Island. That is nearly 80 times the death toll on 9/11, and the effects of those attacks do not end there.

Afghanistan

The Taliban are gone, but in their place are still war, terrorist attacks, corruption on an epic scale and such a formidable opium and cannabis harvest that parts of the country are, in effect, a drugs factory. And, in some areas (notably women's rights and education), gains are being set in reverse. For the nearly $450bn Congress estimates the US alone has spent waging war there, every Afghan man, woman and child could have been handed $15,000 – 10 years' average earnings. Life expectancy is under 45 years, and about a quarter of children don't live to see their fifth birthday. Only one in four adults can read or write.

Iraq

It is a measure of just how bad was the mayhem unleashed by the 2003 invasion that the present reduction of daily sectarian attacks to an average of 14 is regarded as some sort of triumph. But the years-long chaos, bloodshed and breakdown of civil society – only now being slowly rectified – have killed somewhere around 126,000 civilians (the Watson Institute's estimate). Those who survived no longer live in a totalitarian state, and there are open, if deeply flawed, elections. But the neocons' idea that Iraq would become a beacon of democracy in the region has remained a naive pipe dream. It is in other countries that pressure for real change has come, and it has come from the streets, not as a US import.

Al-Qa'ida

Ten years ago this morning, no one knew if the 9/11 attacks were the catastrophic opening bombardments in a constant state of guerrilla war writ horrifically large, or two dozen murderous terrorists who got lucky. Suddenly, al-Qa'ida was credited with the power to bring the developed world to its knees. Despite Bali, Madrid and London, that has not happened – partly because of resources and effort applied to prevent it, partly because of the haphazard nature of al-Qa'ida. And, today, Bin Laden is dead. Sighs of relief would be absurdly premature, and what goes unacknowledged in the West is that most people killed by al-Qa'ida (and there are thousands) are Muslim.

The Muslim world

If the 9/11 attacks were conducted on the premise that the US was antagonistic towards Muslims, the country's reactions to the atrocity have gone a long way towards proving that thesis in the eyes of millions of Muslims. The wars, tortures, drone attacks, suspicion that Arab oil was a major motivator and continued support for Israel have all made relations with the Muslim world poorer, despite President Barack Obama's more intelligent and emollient words. Nothing shows this more clearly than relations with Pakistan, ostensibly an ally in the "war on terror", but, in reality, a dysfunctional nuclear state where many are opposed to the US and all its works. A survey of Pakistanis in June by the Pew Research Center found that 69 per cent saw the US as an enemy.

Security

Airline passengers now have waits of up to two hours, control on liquids over 100ml entering the plane, short-term bans on hand luggage, body scans and the removal of shoes as part of security checks. Entering offices is no longer a matter of breezing past reception, but proving your ID, and visa restrictions abound. By 2008, 45 countries had introduced biometric passports and 100 million had been issued globally. Many planes are now bullet proof, with locked cockpit doors to secure the pilot and flight crew.

Britain

Wars in Afghanistan and Iraq have cost the lives of 559 service personnel, and opened deep divisions back home. The political debate – within and between parties – has been disfigured by the wars. Critics claim they have made Britain a terror target, evidenced by the 7/7 attacks, several foiled plots and the intelligence services' repeated warnings about the threat from radicalised young British Muslims. Campaigners maintain the post-9/11 climate allowed a clampdown on civil liberties – including control orders, enhanced detention powers and identity cards – which has not yet receded.

World economy

The West had spluttered into a post-dotcom downturn by 2001, but 11 September is blamed for accelerating the decline of the US and the world economy. Several analysts claim the response to 9/11 contributed to the global credit boom that eventually started the catastrophic credit-crunch recession years later. But easy credit and the bonus-fuelled gambles of investment bankers inflicted far more damage to economies than Bin Laden ever did.

David Randall, Brian Brady and Nalini Sivathasan

Flight 93 memorial

Former US presidents George W Bush and Bill Clinton yesterday helped to dedicate a memorial in honour of passengers and air crew who fought back against 9/11 hijackers.

The Flight 93 National Memorial marks the spot where passengers and crew foiled the attack on Washington DC 10 years ago. They stormed the cockpit to try to regain control from four terrorists, but the Boeing 757 crashed in a field. There were no survivors. The memorial is part of a new 1,500-acre national park in Shanksville, Pennsylvania.

More than 4,000 people, including relatives of those on board the United Airlines flight, listened to Mr Bush say the fightback was "one of the most courageous acts in American history". Mr Clinton said the 40 who fought the hijackers had given "the entire country an incalculable gift".